Objective: To accelerate the development of scalable, reliable, secure, and interoperable communications and standards for smart grid applications by 2017; and to enable informed decision making by smart grid operators by developing measurement science-based guidelines and tools.
What is the new technical idea? Traditionally, technology decisions have been dictated by offerings of system vendors, while business decisions are regulated by federal, state, and regional regulatory commissions and organizations (e.g. the Federal Energy Regulatory Commission, state Public Utility Commissions, and the North American Electric Reliability Corporation). While there are many choices of communications and networking standards, most of these standards were not developed specifically for smart grid applications. The new technical idea is to work directly with the smart grid stakeholders(utilities, regulators and consumers) and the telecommunication industry (vendors, SDOs, service providers) to identify communication requirements for smart grid applications, evaluate and develop communication standards, and develop guidelines and recommendations on their use and deployment. Also, the introduction of new power distribution technologies will transform the electrical network so that it will resemble regional and continental high speed telecommunications networks, although the transported commodity will be electrical power rather than data. This creates an opportunity to apply well-established analysis and optimization techniques from the telecommunications field to aid in the design of future electrical networks.
What is the research plan? Our research plan is focused on understanding and modeling the power grid user and system behaviors and developing control and communication strategies for achieving the smart grid vision of a more efficient and dynamic electric grid. Our research in FY15 comprises two main thrusts.
1) Algorithms to enforce QoS in electrical networks: Microgrid Scenario Since the electrical distribution network has structural similarities to wired communications networks, several modeling and analysis techniques that have been traditionally used in communications networks, such as routing algorithms, traffic analysis, and call admission control, may be applied for controlling and characterizing the electric grid. In FY14, we examined how storage devices can be positioned to mitigate the effect of network failures. In FY15, we plan on applying techniques developed to guarantee quality of service (QoS) for data traffic flows in communications networks to manage power flows in microgrid networks.
Algorithms that enforce QoS in electrical networks will perform two functions: admission control and policing of admitted flows. Historically, power flows traveled from generators (sources) to customers(sinks). The growing use of distributed power generation using renewable resources (e.g. wind and solar) that fluctuate over time, combined with increasing use of renewable sources located at the customer premises, means that there are additional sources of power flows that an operator must contend with. To assess control algorithms that perform admission and policing of flows from operator owned or customer-owned sources, we need accurate models of user behavior. Previously, we used real world data to characterize customer usage patterns. In FY15, we will extend this work by developing and examining stochastic models that capture the arrival and departure behavior of power flows in a grid that incorporates intermittent sources.
In FY14, we used GridLAB-D to simulate failures in power distribution networks, including integrating of distributed energy resources and cascading failures. We will complete the integration of GridLAB-D withns-3 to produce a closed loop co-simulation framework capturing high level interactions between the electrical and communications systems. In FY15, we will extend this work by examining the behavior of adapted QoS algorithms and the communications network traffic that they generate.
2) Improvements to the smart grid communications network: Wide Area Measurement Systems Scenario Smart grid traffic is structurally different from Internet traffic, as revealed by the use cases developed for PAP 2. The delay and loss requirements for smart grid applications vary widely; some are very tolerant of long delays or lost information (metering), while others demand near-instantaneous data delivery with virtually no loss (wide area measurement systems). Also, the amount of data exchanged can grow very large as in the case of wide area measurement systems. As these systems scale up to a large number of Phasor Measurement Units (PMU), the centralized super-Phasor Data Collector (PDC)architecture becomes untenable. In FY14, we developed the initial stages of the Emulab tesbed that consisted of multiple PMU's communicating with a local PDC. Some of the work was also dedicated to designing a real-time simulation package for message exchanges at the application layer in accordance with the IEEE C37.118 specifications. In FY15, we will continue to expand the testbed to assess the performances of different network architectures, such as a hierarchical PDC, as well as using the test bed to compare the accuracy of various frequency and state estimation techniques. In addition, we plan on assessing the performance of a wide variety of communication protocols such as traffic scheduling, routing, authentication, key management, media access control, and application performance data for multiple scenarios so that methods for improving the performance of communication protocols can be developed.
ITL will continue to lead and contribute to the activities of the SGIP related to wireless and powerline communications. In addition ITL staff will continue to participate in international standard activities (ITU, IEEE 802 and IETF) related to smart grid communications.